Chemical Composition and Formation Process

Prehnite is a calcium aluminum silicate mineral with the formula Ca₂Al₂Si₃O₁₀(OH)₂. Prehnite primarily consists of calcium and aluminum, with additional elements like iron and potassium. It often forms in cavities within volcanic rocks and is associated with minerals such as zeolites, calcite, and quartz. Notably, prehnite can exhibit a phenomenon known as “chatoyancy” or “cat’s eye effect”. When rotated under a light source, a bright line appears to move across the stone


The name “Prehnite” honors Colonel Hendrik Von Prehn, who discovered it in South Africa in the 18th century. “Cape Emerald”: Prehnite has been referred to as “Cape Emerald” due to its green color and its resemblance to emerald. This name highlights its visual appeal and the lush green hues it exhibits.

Mythology and Legends

Electric Cosmology

Mining, Production and Use

Prehnite can be found in stalactitic, botryoidal, reniform, or globular aggregates, with small crystals showing curved faces in various locations worldwide, including South Africa, Australia, and the United States. It is mined and then cut and polished into beads, cabochons, and ornamental pieces, used in jewelry and for its metaphysical properties.